hanson



2 Sheets-Sheet 1.

(N0 Modei.)

' D. B. HANSON.

BAND SAW MILL.

No. 532,663. Patented Jan. 15, 1895..

0. 6. Mama/v InvenZr,

(No Model.) 2 Sheets-Sheet 2.

D. B. HANSON. BAND SAW MILL.

No. 532,663. Patented Jan. 15, 1895.

uimn h. "gmlmmllll D. 5. HANSON Irwerdfir UNITED STATES PATENT O FICONE-HALF TO 7 WISCONSIN.

THE EDWARD P. ALLIS COMPANY, OF MILWAUKEE,

BAN D-SAW MILL.

SPECIFICATION forming part of Letters Patent No. 532,663, dated January1 5, 1895.

Application filed October 24,1894. sei-ai'u'o. 526,851. (No model.)

set forth in Letters Patent of the United States granted to Hinkley,Hanson and Trout on the 14th day of February, 1893, and numbered491,683. r A

The present improvements consist primarily in a novel construction andarrangement of the vertically sliding yoke or frame in which the upperband wheel shaft is carried, whereby the parts are relieved of sidestrain and are enabled to move more freely than under the formerconstruction.

Other features and details will be pointed out in the followingdescription.

Figure 1 isa side elevation of the upper portion of my improved millpartly in section;-

Fig. 2, a top plan View, with the main frame in section and withvariousparts removed; and Fig. 3, a perspective view of the yoke or innersliding frame.

The lower portion of the main frame, the lower band wheel and otherparts not directly involved in the present invention are not representedin the drawings, being of any approved construction, such for instanceas represented in the ferred to. V

A indicates the upper portion of the main frame of a band saw mill,which is preferably of box form. Near the forward edges of the framethere are formed vertical V-guides or ways a,-one side of each of whichis formed by an adjustable plateor bar b, slotted horizontally, andsecured to frame A by bolts or other suitable fastenings.

Within frame A is placed a secondary frame or yoke B, having V-shapedribs 0 at its sides to enter the guides or ways a. This yoke is of theform illustrated in Fig. 3, and is de signed to support and carry theupper bandwheel shaft 0. As the saws vary in length and are liabletostretch or elongate in use, it is necessary to provide adjustment ofthe patent hereinbefore re- ,band wheel 0, and it is for this purposethat the yoke is arranged to slide inways as ex,-

is considerable, and the parts being quite large it is difficult tosecure and maintain a perfect fit of theguiding ribs and Ways unlessprovision be made to take up wear and compensate for expansion andcontraction, hence the necessity of the adjustable strips 1).

For the purpose of supporting, raising and provide vertical screws D,operated by worm gear or otherwise, as indicated in Figs. 1 and 3, andas f ully set forth in the patent herein- .before mentioned. The yokeafter being adjusted to suit the saw, is maintained at such adjustment,but as the saw lengthens somewhat by reason of heating when in use, andas" the strain upon it and upon the upper wheel constantly varies withvariations in the Wood through which it passes, it is necessary toprovide an automatic and yielding or elastic tension, independent of theprimary adjustment noted. This automatic tension is produced by acounterweighted lever E, carried by stirrups or hangers, F, and actingagainst the lower ends of cylindrical pedestals G, through the medium ofrods H,the pedestals carrying at their upper ends the boxes I in whichshaft 0 turns. The stirrups or hangers F are screw threaded, passthrough lugs d projecting from the sides of yoke B, and are brought toand maintained at any desired height by nuts 6 screwed upon the threadedstems of the stirrups above the lugs d, as shown in Fig. 3.

It will be observed upon reference to the several figures that the axesof shaftG, pedestals G, and rods H all occupy a vertical planecoincident wi'ththe middle line of the guides at, a, and that there isconsequently little or no side strain upon the guides. As a consequence,the yoke B moves far more freely within frame A, and the pedestals Gmove more freely within the yoke than where the shaft and pedestals areout of plane with the guides. Moreover, there is less strain upon theframe and yoke, and not so much vibration as there is where the yoke isplaced outside and in front of the main frame.

plained. The strain upon all parts of a ma. chine of this character isvery great, the wear p lowering the yoke or secondary frame B, I

The hangers F maybe made in the form of stirrups, as shown in Fig. 3; orthey may be L-shaped, the horizontal member being the sustaining portionon which lever E rests, as in Fig. 1.

The bearings are ad visably made with knife edges to render the actionsensitive.

The lever E may be conveniently made of two bars of iron or steel,bentto pass around the yoke or sliding frame B, and laid together at theirrear ends, which may be bolted or rivcted as shown. Upon the rear end ofthe lever is hung a heavy weight J, which may be increased or diminishedaccording to the tension desired.

The weight J, preferably made up of independent sections, is carried bya rod or hanger K, provided at its lower end with a disk L. Upon thisdisk and beneath the weight is placed a heavy spiral spring M,sufficient to sustain the weight while at rest, without collapsing orbeing fully compressed. The purpose of this spring is to take up theinitial movement of lever E, and thus to relieve the parts of jar andconcussion. By this provision I also render the tension far moresensitive and responsive to variations in the strain upon the saw andits carrying wheel 0. After the parts are once adjusted, and the mill isput in operation, the weight practically stands still while the levervibrates to take up or give out the saw, the spring M responding to eachand every vibration, however short in time or range, whereas they wouldbe unanswered by the weight alone, owing to its inertia and consequentlyslow action.

By combining the weight and spring I secure the wide range of movementallowed by the weight, together with the great delicacy and promptnessof action due to the spring; whereas by the use of either alone one orthe other desirable quality is lost.

The yoke is represented as cast in one piece with a portion to guard thewheel, suitable strengthening ribs, and stopsf to limit the descent ofthe lever. These stops prevent the pedestals from being unduly elevatedwhen the saw is oh? the wheels.

I As shown in Figs. 1 and 2, the lever E extends through an opening inthe rear side of the frame A, which frame is formed with a recess g, toreceive the weight J. By this arrangement the weight is in a measureinclosed and is consequently not liable to be interfered wit-h, yet isaccessible at all times so that it may be increased or diminished asrequired.

Having thus described my invention, what I claim is 1. In a band sawmill, the combination of a main frame provided with guides, asupplemental frame or yoke movable in said guides, an upper band-wheelshaft, and pedestals or supports for said shaft carried by the yoke,-the axes of the shaft and pedestals being in a common plane with theguides,substautially as and for the purpose set forth.

2. In combination with main frame A provided with guides or ways a,supplemental frame or yoke 13 having ribs a seated in said guides,pedestals G mounted in the yoke B, shaft 0 supported by said pedestals,a counterweighted lever for sustaining the pedestals G, and screws forsustaining the yoke B, the shaft 0 and pedestals G having their axes ina common plane with the guides and ribs a and c.

3. In combination with the main frame of a band saw-mill, a sliding yokeor frame B mounted within the main frame and provided with lugs (Z andwith stopsf. stirrups F carried by said lugs, a lever E carried by thestirrups, pedestals G mounted and movable in the yoke, a band-wheelshaft carried by said pedestals, and rods extending from the lever tothe pedestals, substantially as and for the purpose set forth.

4. In combination with frame A having recess g, shaft C, pedestals Gsupporting said shaft, lever E supporting said pedestals, and weight Jcarried by lever E and located within the recess.

In witness whereof I hereunto set my hand in the presence of twowitnesses.

DEMPSEY B. HANSON.

\Vitnesses:

NORMAN A. Roor, J OHN SIMONDS.

